The objective of this study is to determine the prevalence and natural history of pulmonary and cardiac complications associated with HIV infection in utero, in infancy and during early childhood. The objective will be accomplished by establishing a prospective multicenter collaborative study. The study will include the following categories of patients: 1) infants and young children with symptomatic HIV infection acquired by the prenatal route (35 subjects); 2) newborn of women in whom HIV antibody tests were positive during pregnancy (mothers will be enrolled during pregnancy and pre- and post-natal course of infants will be followed--35 subjects). The subjects will be followed prospectively for 2 to 4 years. The types, incidence, course, and outcomes of pulmonary and cardiovascular disorders in these children will be determined. The resources of the Mount Sinai School of Medicine and its affiliated hospitals will be used to enhance recruitment. Coordination with other AIDS trials in women and children carried out in this institution will be attempted to maximize recruitment. The program will be divided into three phases. In Phase I, the protocol and data forms will be developed (1 year). Phase II will be the period of recruitment, study and follow up of the subjects (4 1/2 years). Phase III will involve data analysis (1 year).